1. Field of the Invention
The present invention relates to an apparatus, a method, and a computer program. More particularly, the present invention is applicable to control of post-processing for a sheet on which an image is formed.
2. Description of the Related Art
In recent years, Print On Demand (POD) has emerged against the printing industry with the increasing speeds and the improved image qualities of electrophotographic printing apparatuses and ink-jet printing apparatuses. The POD is intended to process jobs in smaller lots, compared with those processed in the printing apparatuses, at short delivery times without using large-scale apparatuses or systems. For example, POD markets that have emerged make the best use of digital image forming apparatuses, such as digital copiers and digital multifunction machines, to realize digital printing using electronic data in order to do business.
In such POD markets, digitalization penetrates into systems and management and control using computers have prevailed, compared with the printing industry in related art. The use of computers causes the level (for example, the quality) of the POD markets to come close to the level of the printing industry to some extent. In such a background, the POD markets include printing services in copy-print shops and printing companies and printing services for intra-company.
Near-line finishers have come into use as finisher apparatuses, along with in-line finishers physically connected to image processing apparatuses. The near-line finishers are physically separated from image processing apparatuses but are connected to the image processing apparatuses via networks so as to be communicable with the image processing apparatuses.
In a typical system using a near-line finisher, after printing is finished in an image processing apparatus, an operator carries printed sheets to the near-line finisher where post-processing for the printed sheets is performed. In a job using the near-line finisher, the operator inputs a parameter indicating where the post-processing is performed on a sheet based on the size of the sheet used in the printing.
In such a system, the size of the sheet can be varied with time after the printing due to the effect of the heat generated in fixing of toner in the image processing apparatus and/or the effect of the temperature and humidity of a room where the printed sheets are left. The variation in the sheet size may cause the post-processing not to perform at a position which the operator has specified. As measures against this matter, a technology is proposed in which information about the amount of expansion or contraction in the conveying direction of sheets is detected to change the registration position in a finisher apparatus based on the amount of expansion or contraction (refer to Japanese Patent Laid-Open No. 2007-8690).
However, since only the amount of expansion or contraction in the conveying direction of sheets is detected in the above technology, positive effects can be expected only in specific post-processing, such as saddle stitching. Accordingly, there may be a case in that outputs are not produced due to the variation in the sheet size depending on the content of the post-processing.
In addition, there is also a be a case in that only the change of the registration position in the finisher apparatus does not allow precise adjustment of the position where the post-processing is performed because the sizes of image areas are also expanded or contracted due to the expansion or contraction of the sheets. For example, if trimming at the boundary between an image area and a blank area is set for a printed sheet having an image printed on the entire sheet, a part can possibly be trimmed or not depending on the trimming position that is shifted due to the extraction or contraction of the sheet.